In verses 4 and 6 we read of two kinds of sendings. In verse 4 Paul says that God sent forth His Son, and in verse 6, that God sent forth the Spirit of His Son. According to the promise in Genesis 3:15, Christ came under law as the seed of the woman in order to redeem those who were under law, that they might receive the sonship. The goal of Christ’s redemption is not heaven, as many Christians believe; it is sonship. Christ redeemed us so that we may have God’s sonship. Through His redemption, He has opened the way for us to possess the sonship. However, if the Spirit had not come, our sonship would be empty. It would be a sonship in position or form, not a sonship with reality. The reality of sonship, which depends on life and maturity, comes only by the Spirit. Therefore, verse 6 declares that God has sent forth the Spirit of His Son into our hearts.
We should not believe that the Spirit of the Son is a person separate from the Son. Actually, the Spirit of the Son is another form of the Son. We have pointed out that the One who was crucified on the cross was Christ, but the One who enters into the believers is the Spirit. In crucifixion for our redemption, this One was Christ, but in the indwelling to be our life, He is the Spirit. When the Son died on the cross, He was Christ, but when He enters into us, He is the Spirit. First He came as the Son under the law to qualify us for sonship and to open the way for us to share in the sonship. But after He had finished this work, He became, in resurrection, the life-giving Spirit and comes to us as the Spirit of the Son. Thus, first God the Father sent the Son to accomplish redemption and to qualify us for sonship. Then He sent the Spirit to vitalize the sonship and to make it real in our experience. Today sonship actually depends upon the Spirit of God’s Son.
In verse 6 Paul says that God sent forth the Spirit of His Son into our hearts. Actually the Spirit of God came into our spirit at our regeneration (John 3:6; Rom. 8:16). Because our spirit is hidden in our heart (1 Pet. 3:4), and because the word here refers to a matter that is related to our feeling and understanding, both of which belong to our heart, it says that the Spirit of God’s Son was sent into our heart.
Romans 8:15 is a verse that is parallel to Galatians 4:6. Romans 8:15 says that we who have received a spirit of sonship cry, in this spirit, Abba, Father, whereas Galatians 4:6 says that the Spirit of God’s Son is crying in our heart, Abba, Father. This indicates that our regenerated spirit and the Spirit of God are mingled as one, and that our spirit is in our heart. This also indicates that with us the sonship of God is realized by our subjective experience in the depths of our being. In this verse Paul appeals to such an experience of the Galatian believers for his revelation. This appeal is quite convincing and subduing, not merely because of the objective doctrines, but because of the experiential facts.
Abba is an Aramaic word, thus a Hebrew word, and Father is the translation of the Greek word pater. Such a term was first used by the Lord Jesus in Gethsemane while praying to the Father (Mark 14:36). The combination of the Hebrew title with the Greek expresses a stronger affection in crying to the Father. Such an affectionate cry implies an intimate relationship in life between a genuine son and a begetting father.
As humans we have not only a spirit, but we also have our person, our being. The center of our person is our heart. For us to become sons of God not only involves our spirit, but also involves our heart as the center of our personality. The New Testament clearly reveals that the spirit is in the heart (1 Pet. 3:4). Therefore, it is not possible for the Spirit to be sent into our spirit without also being sent into our heart. It is important for us to realize that our spirit is the kernel, the central part, of our heart. When God’s Spirit was sent into our spirit, the Spirit was sent into the kernel of our heart. When the Spirit cries within us, He cries from our spirit and through our heart. Hence, concerning sonship, our heart must be involved.
The inner sense we have as we call on the Lord from our spirit through our heart is mainly in the heart, not in the spirit. This implies that to be genuinely spiritual we need to be emotional in a proper way. Brother Nee once said that a person who cannot laugh or cry cannot be truly spiritual. We are not senseless statues; we are human beings with feelings. Therefore, the more we cry, Abba, Father, in the spirit, the deeper will be the sweet and intimate sense in our heart.
The sense we have when calling in this way is sweet and intimate. Although the Spirit of sonship has come into our spirit, the Spirit cries in our hearts, Abba, Father. This indicates that our relationship with our Father in the sonship is sweet and very intimate. For example, when a son calls his father “Daddy,” there may be a sweet and intimate sense deep within. However, the sense is not the same if he tries to say the same thing to his father-in-law. The reason is that with the father-in-law there is no relationship in life. But how sweet it is when little children, enjoying a relationship in life with their fathers, say tenderly, “Daddy.” In like manner, how tender and sweet it is to call God, Abba, Father! Such an intimate calling involves our emotion as well as our spirit. The Spirit of sonship in our spirit cries, Abba, Father, from our heart. This proves that we have a genuine, bona fide relationship in life with our Father. We are His real sons.
Since we have the Spirit of sonship, we no longer need to be held under the custody of the law. We do not need the law to be our guardian, steward, or child-conductor. In 4:7 Paul says, “So you are no longer a slave, but a son; and if a son, an heir also through God.” The New Testament believer is no longer a slave to works under law, but a son in life under grace. Instead of the law to keep us in custody, we have the all-inclusive Spirit. This Spirit is everything to us. Whereas the law could not give life, the Spirit gives life and brings us into maturity that we may have the full position and right of sons. The custody of the law has been replaced by the Spirit of sonship.
As sons, we are also heirs through God. An heir is one who is of full age according to the law (the Roman law is used for illustration) and who is qualified to inherit the Father’s estate. The New Testament believers become heirs of God not through the law or through their fleshly father, but through God, even the Triune God—the Father who sent forth the Son and the Spirit (vv. 4, 6), the Son who accomplished redemption for sonship (v. 5), and the Spirit who carries out the sonship within us (v. 6).